Flame-resistant polycarbonate molding compositions containing high-purity talc

ABSTRACT

The present invention relates to polycarbonate compositions filled with talc which, in addition to excellent flame resistance, are distinguished even at small wall thicknesses by improved rigidity, good resistance to stress cracking, that is to say resistance to chemicals, and by low tool abrasion and low coating formation during processing.

[0001] The present invention relates to polycarbonate compositionsfilled with talc which, in addition to excellent flame resistance, aredistinguished even at small wall thicknesses by improved rigidity, goodresistance to stress cracking, i.e. resistance to chemicals, and by lowtool abrasion and low coating formation (“juicing”) during processing.

[0002] Filled or reinforced PC/ABS moulding compositions are known.

[0003] EP-A 0 391 413 describes, for example, PC/ABS mouldingcompositions containing inorganic fillers having particular geometricproperties, the moulding compositions being specified by a relativelylow linear thermal expansion coefficient, high strength under impactloading, and a high dimensional stability under heat. Talc anduncalcined clay materials are described as fillers according to theinvention. Flameproofing agents are mentioned only generally in a groupof additives.

[0004] In EP-A 0 452 788 there are described talc-containing PC/ABSmoulding compositions which are distinguished especially by a mattsurface of the material. Here too, flameproofing agents are mentionedonly generally.

[0005] Filled or reinforced PC/ABS moulding compositions which have beenrendered flame-resistant are also already known.

[0006] JP-A 0 219 9162 describes reinforced, flame-resistant PC/ABSmoulding compositions provided with a halogen-containing flameproofingagent having a halogen content of from 0.5 to 15 wt. %. Talc ismentioned generally as a possible filler.

[0007] EP-A 0 363 608 and EP-A 0 640 655 relate to PC/ABS mouldingcompositions which have been rendered flame-resistant byoligophosplioric acid esters or mixtures of oligo- and mono-phosphoricacid esters. It is mentioned in general that the moulding compositionsmay contain reinforcing materials. Examples of reinforced mouldingcompositions are not disclosed, however.

[0008] WO 99/07778 describes reinforced PC/ABS moulding compositionswhich have been rendered flame-resistant by organic phosphoruscompounds, the polycarbonate content of those moulding compositionsbeing a mixture of two aromatic polycarbonates having different solutionviscosities. Only the use of glass fibres as reinforcing agent isdemonstrated by means of examples. Those lead to undesirable toolabrasion during processing of the moulding composition. WO 99/07778teaches that PC/ABS moulding compositions having a better modulus ofelasticity, notched bar impact strength and processing properties areobtained when particular mixtures of polycarbonates of differentviscosities are used.

[0009] In EP-A 0 754 531 it is mentioned that the use of fibrous fillershaving a high L/D ratio leads to products having anisotropic properties(tensile strength, rigidity, linear thermal expansion coefficient,shrinkage ratio), which often has undesirable consequences such aswarping, deformation on heating, etc. There is described a PC/ABSmoulding composition which has been rendered flame-resistant by the useof particular oligophosphoric acid esters and reinforced by a fillerhaving a lamellar structure. Examples containing glass flakes, micas andmixtures thereof as filler are disclosed in particular. Talc is notmentioned explicitly as a filler. EP-A 754 531 teaches that thedescribed moulding compositions are distinguished by low deformation inthe case of variations in temperature, allowing them to be used forhigh-precision components. Further advantages mentioned are a lowtendency towards bleeding of the flameproofing agent and towards theformation of a coating in the injection-moulding tool.

[0010] JP-A 0 731 6411 describes PC/ABS moulding compositions whichcontain from 1 to 30% of an aromatic monophosphate as flameproofingagent and from 1 to 20% of a calcined talc having an average particlesize of 2 μm or less as filler. The moulding compositions aredistinguished by good processability, strength and dimensional stabilityunder heat as well as by excellent flame protection. Experience teaches,however, that monophosphates tend to bleed and to form undesirablecoatings on the tools during processing by injection moulding.

[0011] U.S. Pat. No. 5,849,827 and WO 99/07788 disclose flame-resistantthermoplastic moulding compositions, based on polycarbonate, whichcontain very finely divided inorganic powders. Talc is not mentioned. Itis described that, by the addition of the finely divided inorganicpowders, the after-burning times at 1.6 mm according to UL 94 V, andhence the flameproofing properties, are improved.

[0012] The object of the present invention is to improve the flameresistance (reduction of the after-burning times and dripping tendencyin the UL 94 V test) in the case of thin wall thicknesses, especially of1.5 mm and below, while at the same time increasing the rigidity of thematerial, which is especially important in the case of thin-walledmouldings. Furthermore, the moulding compositions are to have goodresistance to stress cracking, good hydrolytic stability, a low warpingtendency, good flowability, dimensional stability under heat andstrength and, during processing, negligible tool abrasion and negligiblecoating formation as a result of bleeding of the flameproofing agentduring processing.

[0013] It has now been found that impact-modified polycarbonatecompositions which contain the particular talc described below have thedesired properties. The profile of properties of the compositionsaccording to the invention especially permits their use in theproduction of thin-walled mouldings, especially for applications whichrequire reliable flame protection.

[0014] Accordingly, the present invention provides polycarbonatecompositions containing impact modifier, at least onephosphorus-containing flameproofing agent, and

[0015] from 0.05 to 40 parts by weight, preferably from 0.5 to 30 partsby weight, particularly preferably from 1 to 20 parts by weight, basedon the total composition, of a particular highly pure talc having an MgOcontent of from 28 to 35 wt. %, preferably from 30 to 33 wt. %,particularly preferably from 30.5 to 32 wt. %, and an SiO₂ content offrom 55 to 65 wt. %, preferably from 58 to 64 wt. %, particularlypreferably from 60 to 62.5 wt. %, in each case based on the talc.

[0016] Especially preferred types of talc are further distinguished byan Al₂O₃ content of less than 5 wt. %, especially less than 1 wt. %,more especially less than 0.7 wt. %, based on the talc.

[0017] Preference is given to polycarbonate compositions containing

[0018] A) from 40 to 98 parts by weight, preferably from 45 to 95 partsby weight, particularly preferably from 50 to 90 parts by weight, of atleast one aromatic polycarbonate,

[0019] B) from 0.5 to 50 parts by weight, preferably from 1 to 35 partsby weight, particularly preferably from 1.5 to 25 parts by weight, of atleast one graft polymer,

[0020] C) from 0.5 to 40 parts by weight, especially from 2 to 20 partsby weight, of at least one phosphorus-containing flameproofing agent,

[0021] D) from 0.05 to 40 parts by weight, especially from 0.5 to 30parts by weight, particularly preferably from 1 to 20 parts by weight,of a talc according to the above definition.

[0022] The sum of the parts by weight of all the components (A to D and,optionally, further constituents) is 100.

[0023] Very particularly preferred polycarbonate compositions aredistinguished especially by the fact that, at wall thicknesses of lessthan or equal to 1.5 mm, preferably at wall thicknesses of 1.2 mm orless, they pass the UL 94V test with the rating V-0.

[0024] Component A

[0025] Aromatic polycarbonates and/or aromatic polyester carbonatesaccording to component A which are suitable according to the inventionare known in the literature or can be prepared by processes which areknown in the literature (for the preparation of aromatic polycarbonatessee, for example, Schnell, “Chemistry and Physics of Polycarbonates”,Interscience Publishers, 1964 and DE-AS 1 495 626, DE-OS 2 232 877,DE-OS 2 703 376, DE-OS 2 714 544, DE-OS 3 000 610, DE-OS 3 832 396; forthe preparation of aromatic polyester carbonates see, for example, DE-OS3 077 934).

[0026] The preparation of aromatic polycarbonates is carried out, forexample, by reacting diphenols with carbonic acid halides, preferablyphosgene, and/or with aromatic dicarboxylic acid dihalides, preferablybenzenedicarboxylic acid dihalides, by the interfacial process,optionally using chain terminators, for example monophenols, andoptionally using branching agents having a functionality of three ormore than three, for example triphenols or tetraphenols.

[0027] Diphenols for the preparation of aromatic polycarbonates and/oraromatic polyester carbonates are preferably those of formula (I)

[0028] wherein

[0029] A represents a single bond, C₁-C₅-alkylene, C₂-C₅-alkylidene,C₅-C₆-cycloalkylidene, —O—, —SO—, —CO—, —S—, —SO₂—, C₆-C₁₂-arylene, towhich there may be condensed other aromatic rings optionally containinghetero atoms, or a radical of formula (II) or (III)

[0030] each of the substituents B represents C₁-C₁₂-alkyl, preferablymethyl, halogen, preferably chlorine and/or bromine,

[0031] the substituents x are each independently of the other 0, 1 or 2

[0032] p represents 1 or 0, and

[0033] R⁵ and R⁶ can be selected individually for each X¹ and are eachindependently of the other hydrogen or C₁-C₆-alkyl, preferably hydrogen,methyl or ethyl,

[0034] X¹ represents carbon, and

[0035] m represents an integer from 4 to 7, preferably 4 or 5, with theproviso that at at least one atom X¹, R⁵ and R⁶ are simultaneouslyalkyl.

[0036] Preferred diphenols are hydroquinone, resorcinol,dihydroxydiphenols, bis-(hydroxyphenyl)-C₁-C₅-alkanes,bis-(hydroxyphenyl)-C₅-C₆-cycloalkanes, bis-(hydroxyphenyl) ethers,bis-(hydroxyphenyl) sulfoxides, bis-(hydroxyphenyl) ketones,bis-(hydroxyphenyl)-sulfones andα,α-bis-(hydroxyphenyl)-diisopropylbenzenes and their derivativesbrominated and/or chlorinated at the nucleus.

[0037] Particularly preferred diphenols are 4,4′-dihydroxydiphenyl,bisphenol A, 2,4-bis-(4-hydroxyphenyl)-2-methylbutane,1,1-bis-(4-hydroxyphenyl)-cyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,4,4′-dihydroxydiphenyl sulfide, 4,4′-di-hydroxydiphenyl-sulfone andtheir di- and tetra-brominated or -chlorinated derivatives, such as, forexample, 2,2-bis-(3-chloro-4-hydroxyphenyl)-propane,2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane or2,2-bis-(3,5-dibromo-4-hydroxy-phenyl)-propane.

[0038] 2,2-Bis-(4-hydroxyphenyl)-propane (bisphenol A) is particularlypreferred.

[0039] The diphenols may be used individually or in the form of anydesired mixtures.

[0040] The diphenols are known in the literature or obtainable byprocesses known in the literature.

[0041] Suitable chain terminators for the preparation of thermoplasticaromatic polycarbonates are, for example, phenol, p-chlorophenol,p-tert.-butylphenol or 2,4,6-tribromophenol, as well as long-chainedalkylphenols, such as 4-(1,3-tetra-methylbutyl)-phenol according toDE-OS 2 842 005 or monoalkylphenols or dialkylphenols having a total offrom 8 to 20 carbon atoms in the alkyl substituents, such as3,5-di-tert.-butylphenol, p-isooctylphenol, p-tert.-octylphenol,p-dodecylphenol and 2-(3,5-dimethylheptyl)-phenol and4-(3,5-dimethylheptyl)-phenol. The amount of chain terminators to beused is generally from 0.5 mol % to 10 mol %, based on the molar sum ofthe diphenols used in a particular case.

[0042] The thermoplastic aromatic polycarbonates have meanweight-average molecular weights (M_(w), measured, for example, by meansof an ultracentrifuge or by scattered-light measurement) of from 10,000to 200,000, preferably from 15,000 to 80,000.

[0043] The thermoplastic aromatic polycarbonates may be branched in aknown manner, preferably by the incorporation of from 0.05 to 2.0 mol %,based on the sum of the diphenols used, of compounds having afunctionality of three or more than three, for example compounds havingthree or more phenolic groups.

[0044] Both homopolycarbonates and copolycarbonates are suitable. Forthe preparation of copolycarbonates according to component A accordingto the invention, from 1 to 25 wt. %, preferably from 2.5 to 25 wt. %(based on the total amount of diphenols to be used) ofpolydiorganosiloxanes having hydroxy-aryloxy terminal groups may also beused. Those compounds are known (see, for example, U.S. Pat. No.3,419,634) or can be prepared by processes known in the literature. Thepreparation of copolycarbonates containing polydiorganosiloxanes isdescribed, for example, in DE-OS 3 334 782.

[0045] In addition to the homopolycarbonates of bisphenol A, preferredpolycarbonates are the copolycarbonates of bisphenol A containing up to15 mol %, based on the molar sum of diphenols, of diphenols other thanthose mentioned as being preferred or particularly preferred, especially2,2-bis-(3,5-dibromo-4-hydroxyphenyl)-propane.

[0046] Aromatic dicarboxylic acid dihalides for the preparation ofaromatic polyester carbonates are preferably the diacid dichlorides ofisophthalic acid, terephthalic acid, diphenyl ether 4,4′-dicarboxylicacid and naphthalene-2,6-dicarboxylic acid.

[0047] Special preference is given to mixtures of the diacid dichloridesof isophthalic acid and terephthalic acid in a ratio of from 1:20 to20:1.

[0048] In the preparation of polyester carbonates, a carbonic acidhalide, preferably phosgene, is additionally used concomitantly asbifunctional acid derivative.

[0049] In addition to the monophenols already mentioned, there come intoconsideration as chain terminators for the preparation of the aromaticpolyester carbonates also the chlorocarbonic acid esters of thementioned monophenols and the acid chlorides of aromatic monocarboxylicacids, which may optionally be substituted by C₁-C₂₂-alkyl groups or byhalogen atoms, as well as aliphatic C₂-C₂₂-monocarboxylic acidchlorides.

[0050] The amount of chain terminators is in each case from 0.1 to 10mol %, based in the case of phenolic chain terminators on moles ofdiphenols and in the case of monocarboxylic acid chloride chainterminators on moles of dicarboxylic acid dichlorides.

[0051] The aromatic polyester carbonates may also contain aromatichydroxycarboxylic acids incorporated therein.

[0052] The aromatic polyester carbonates may be either linear orbranched in a known manner (see in that connection also DE-OS 2 940 024and DE-OS 3 007 934).

[0053] There may be used as branching agents, for example, carboxylicacid chlorides having a functionality of three or more, such as trimesicacid trichloride, cyanuric acid trichloride,3,3′-,4,4′-benzophenone-tetracarboxylic acid tetrachloride,1,4,5,8-naphthalenetetracarboxylic acid tetrachloride or pyromelliticacid tetrachloride, in amounts of from 0.01 to 1.0 mol % (based ondicarboxylic acid dichlorides used), or phenols having a functionalityof three or more, such as phloroglucinol,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene,2,4-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane,1,3,5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)ethane,tri-(4-hydroxyphenyl)-phenylmethane,2,2-bis[4,4-bis(4-hydroxyphenyl)cyclohexyl]-propane,2,4-bis(4-hydroxyphenyl-isopropyl)-phenol,tetra-(4-hydroxyphenyl)-methane,2,6-bis(2-hydroxy-5-methyl-benzyl)-4-methylphenol,2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane,tetra-(4-[4-hydroxyphenyl-isopropyl]-phenoxy)-methane,1,4-bis[4,4′-dihydroxy-triphenyl)-methyl]-benzene, in amounts of from0.01 to 1.0 mol %, based on diphenols used. Phenolic branching agentscan be used initially with the diphenols, acid chloride branching agentscan be introduced together with the acid dichlorides.

[0054] The content of carbonate structural units in the thermoplasticaromatic polyester carbonates can vary as desired. The carbonate groupcontent is preferably up to 100 mol %, especially up to 80 mol %,particularly preferably up to 50 mol %, based on the sum of ester groupsand carbonate groups. Both the esters and the carbonates contained inthe aromatic polyester carbonates can be present in the polycondensationproduct in the form of blocks or in a randomly distributed manner.

[0055] The relative solution viscosity (η_(rel)) of the aromaticpolycarbonates and polyester carbonates is in the range of from 1.18 to1.4, preferably from 1.20 to 1.32 (measured on solutions of 0.5 g ofpolycarbonate or polyester carbonate in 100 ml of methylene chloridesolution at 25° C.).

[0056] The thermoplastic aromatic polycarbonates and polyestercarbonates may be used alone or in any desired mixture.

[0057] Component B

[0058] Component B contains one or more graft polymers of

[0059] B.1 from 5 to 95 wt. %, preferably from 30 to 90 wt. %, of atleast one vinyl monomer with

[0060] B.2 from 95 to 5 wt. %, preferably from 70 to 10 wt. %, of one ormore graft bases having glass transition temperatures <10° C.,preferably <0° C., particularly preferably <−20° C.

[0061] The graft base B.2 generally has a mean particle size (d₅₀ value)of from 0.05 to 10 μm, preferably from 0.1 to 5 μm, particularlypreferably from 0.2 to 1 μm.

[0062] Monomers B.1 are preferably mixtures of

[0063] B.1.1 from 50 to 99 parts by weight of vinyl aromatic compoundsand/or vinyl aromatic compounds substituted at the nucleus (such as, forexample, styrene, α-methylstyrene, p-methylstyrene, p-chlorostyrene)and/or methacrylic acid (C₁-C₈)-alkyl esters (such as, for example,methyl methacrylate, ethyl methacrylate), and

[0064] B.1.2 from 1 to 50 parts by weight of vinyl cyanides (unsaturatednitrites, such as acrylonitrile and methacrylonitrile) and/or(meth)acrylic acid (C₁-C₈)-alkyl esters (such as, for example, methylmethacrylate, n-butyl acrylate, tert.-butyl acrylate) and/or derivatives(such as anhydrides and imides) of unsaturated carboxylic acids (forexample maleic anhydride and N-phenyl-maleimide).

[0065] Preferred monomers B.1.1 are selected from at least one of themonomers styrene, α-methylstyrene and methyl methacrylate; preferredmonomers B.1.2 are selected from at least one of the monomersacrylonitrile, maleic anhydride and methyl methacrylate.

[0066] Particularly preferred monomers are B.1.1 styrene and B.1.2acrylonitrile.

[0067] Suitable graft bases B.2 for the graft polymers B are, forexample, diene rubbers, EP(D)M rubbers, that is to say those based onethylene/propylene and optionally diene, acrylate, polyurethane,silicone, chloroprene and ethylene/vinyl acetate rubbers.

[0068] Preferred graft bases B.2 are diene rubbers (for example based onbutadiene, isoprene, etc.) or mixtures of diene rubbers or copolymers ofdiene rubbers or mixtures thereof with other copolymerisable monomers(for example according to B.1.1 and B.1.2), with the proviso that theglass transition temperature of component B.2 is below <10° C.,preferably <0° C., particularly preferably <−10° C.

[0069] Special preference is given to pure polybutadiene rubber.

[0070] Particularly preferred polymers B are, for example, ABS polymers(emulsion, mass and suspension ABS), as are described, for example, inDE-OS 2 035 390 (=U.S. Pat. No. 3,644,574) or in DE-OS 2 248 242 (=GB-PS1 409 275) or in Ullmann, Enzyklopädie der Technischen Chemie, Vol. 19(1980), p. 280 ff. The gel content of the graft base B.2 is at least 30wt. %, preferably at least 40 wt. % (measured in toluene).

[0071] The graft copolymers B are prepared by free-radicalpolymerisation, for example by emulsion, suspension, solution or masspolymerisation, preferably by emulsion or mass polymerisation.

[0072] Particularly suitable graft rubbers are also ABS polymers whichare prepared by redox initiation using an initiator system of organichydroperoxide and ascorbic acid according to U.S. Pat. No. 4,937,285.

[0073] Since it is known that the graft monomers are not necessarilygrafted on to the graft base completely in the graft reaction, graftpolymers B are also to be understood according to the invention as beingproducts that are obtained by (co)polymerisation of the graft monomersin the presence of the graft base and that are also obtained duringworking up.

[0074] Suitable acrylate rubbers according to B.2 for the polymers B arepreferably polymers of acrylic acid alkyl esters, optionally with up to40 wt. %, based on B.2, of other polymerisable, ethylenicallyunsaturated monomers. The preferred polymerisable acrylic acid estersinclude C₁-C₈-alkyl esters, for example methyl, ethyl, butyl, n-octyland 2-ethylhexyl esters; haloalkyl esters, preferably halo-C₁-C₈-alkylesters, such as chloroethyl acrylate, as well as mixtures of thosemonomers.

[0075] For crosslinking, monomers having more than one polymerisabledouble bond can be copolymerised. Preferred examples of crosslinkingmonomers are esters of unsaturated monocarboxylic acids having from 3 to8 carbon atoms and of unsaturated monohydric alcohols having from 3 to12 carbon atoms, or of saturated polyols having from 2 to 4 OH groupsand from 2 to 20 carbon atoms, such as, for example, ethylene glycoldimethacrylate, allyl methacrylate; polyunsaturated heterocycliccompounds, such as, for example, trivinyl and triallyl cyanurate;polyfunctional vinyl compounds, such as di- and tri-vinylbenzenes; andalso triallyl phosphate and diallyl phthalate.

[0076] Preferred crosslinking monomers are allyl methacrylate, ethyleneglycol dimethacrylate, diallyl phthalate and heterocyclic compoundshaving at least three ethylenically unsaturated groups.

[0077] Particularly preferred crosslinking monomers are the cyclicmonomers triallyl cyanurate, triallyl isocyanurate,triacryloylhexahydro-s-triazine, triallyl benzenes. The amount ofcrosslinking monomers is preferably from 0.02 to 5 wt. %, especiallyfrom 0.05 to 2 wt. %, based on the graft base B.2.

[0078] In the case of cyclic crosslinking monomers having at least threeethylenically unsaturated groups, it is advantageous to limit the amountto less than 1 wt. % of the graft base B.2.

[0079] Preferred “other” polymerisable, ethylenically unsaturatedmonomers which can optionally be used, in addition to the acrylic acidesters, for the preparation of the graft base B.2 are, for example,acrylonitrile, styrene, α-methylstyrene, acrylamides, vinyl C₁-C₆-alkylethers, methyl methacrylate, butadiene. Preferred acrylate rubbers asgraft base B.2 are emulsion polymers having a gel content of at least 60wt. %.

[0080] Other suitable graft bases according to B.2 are silicone rubbershaving graft-active sites, as are described in DE-OS 3 704 657, DE-OS 3704 655, DE-OS 3 631 540 and DE-OS 3 631 539.

[0081] The gel content of the graft base B.2 is determined at 25° C. ina suitable solvent (M. Hoffmann, H. Krömer, R. Kuhn, Polymeranalytik Iund II, Georg Thieme-Verlag, Stuttgart 1977).

[0082] The mean particle size d₅₀ is the diameter above and below whichin each case 50 wt. % of the particles lie. It can be determined bymeans of ultracentrifuge measurement (W. Scholtan, H. Lange, Kolloid, Z.und Z. Polymere 250 (1972), 782-1796).

[0083] Component C

[0084] Phosphorus-containing flameproofing agents within the scope ofthe invention are preferably selected from the groups of the monomericand oligomeric phosphoric and phosphonic acid esters, phosphonate aminesand phosphazenes, it being possible to use as flameproofing agents alsomixtures of several components selected from one or various of thosegroups. Other phosphorus compounds not mentioned specifically here mayalso be used alone or in any desired combination with other phosphoruscompounds.

[0085] Halogen-free phosphorus compounds are preferably used.

[0086] Preferred monomeric and oligomeric phosphoric and phosphonic acidesters are phosphorus compounds of the general formula (IV)

[0087] wherein

[0088] R¹, R², R³ and R⁴ are each independently of the others optionallyhalogenated C₁- to C₈-alkyl, or C₅- to C₆-cycloalkyl, C₆- to C₂₀-aryl orC₇- to C₁₂-aralkyl each optionally substituted by alkyl, preferablyC₁-C₄-alkyl, and/or by halogen, preferably chlorine, bromine,

[0089] the substituents n are each independently of the others 0 or 1,

[0090] q represents from 0 to 30, and

[0091] X represents a mono- or poly-nuclear aromatic radical having from6 to 30 carbon atoms, or a linear or branched aliphatic radical havingfrom 2 to 30 carbon atoms which may be OH-substituted and contain up to8 ether bonds.

[0092] R¹, R², R³ and R⁴ are each independently of the others preferablyC₁-C₄-alkyl, phenyl, naphthyl or phenyl-C₁-C₄-alkyl. The aromatic groupsR¹, R², R³ and R⁴ may in turn be substituted by halogen and/or alkylgroups, preferably chlorine, bromine and/or C₁-C₄-alkyl. Particularlypreferred aryl radicals are cresyl, phenyl, xylenyl, propylphenyl orbutylphenyl and the corresponding brominated and chlorinated derivativesthereof.

[0093] X in formula (IV) preferably represents a mono- or poly-nucleararomatic radical having from 6 to 30 carbon atoms. It is preferablyderived from diphenols of formula (I).

[0094] Each of the substituents n in formula (IV), independently of theothers, may be 0 or 1; n is preferably 1.

[0095] q represents values from 0 to 30. When mixtures of variouscomponents of formula (IV) are used, such mixtures may preferably havenumber-averaged q values from 0.3 to 20, particularly preferably from0.5 to 10, especially from 0.5 to 6.

[0096] X is particularly preferably

[0097] or their chlorinated or brominated derivatives; X is derivedespecially from resorcinol, hydroquinone, bisphenol A or4,4′-dihydroxydiphenyl. X is particularly preferably derived frombisphenol A.

[0098] It has proved particularly advantageous to use oligomericphosphoric acid esters of the general formula (IVa)

[0099] in which

[0100] R¹, R², R³, R⁴ and n are as defined above,

[0101] the substituents 1 are each independently of the other 0, 1, 2, 3or 4, preferably 0, 1 or 2,

[0102] q is from 0.3 to 20, preferably from 0.5 to 10, especially from0.5 to 6,

[0103] R⁵ and R⁶ are each independently of the other C₁-C₄-alkyl,preferably methyl, and

[0104] Y represents C₁-C₇-alkylidene, C₁-C₇-alkylene,C₅-C₁₂-cycloalkylene, C₅-C₁₂-cycloalkylidene, —O—, —S—, —SO—, SO₂ or—CO—, preferably C₁-C₇-alkylidene, especially isopropylidene or methyl.

[0105] Compositions provided with such phosphorus compounds exhibit aparticularly high stress cracking resistance and hydrolytic stabilityand a particularly low tendency to form a coating during processing byinjection moulding. Furthermore, an especially high dimensionalstability under heat can be achieved with those flameproofing agents.

[0106] Particular preference is given to the use of those compounds ofthe general formula (IVa) that are derived from bisphenol A.

[0107] There may be used as component C according to the inventionmonophosphates (q=0), oligophosphates (q=from 1 to 30) or mixtures ofmono- and oligo-phosphates.

[0108] Monophosphorus compounds of formula (IV) are especially tributylphosphate, tris-(2-chloroethyl) phosphate, tris-(2,3-dibromopropyl)phosphate, triphenyl phosphate, tricresyl phosphate, diphenylcresylphosphate, diphenyloctyl phosphate, diphenyl-2-ethylcresyl phosphate,tri-(isopropylphenyl) phosphate, halo-substituted aryl phosphates,methylphosphonic acid dimethyl esters, methylphosphonic acid diphenylesters, phenylphosphonic acid diethyl esters, triphenylphosphine oxideor tricresylphosphine oxide.

[0109] The phosphorus compounds according to component C. formula (IV)are known (see, for example, EP-A 363 608, EP-A 640 655) or can beprepared in an analogous manner by known methods (for example UllmannsEncyklopädie der technischen Chemie, Vol. 18, p. 301 ff 1979;Houben-Weyl, Methoden der organischen Chemie, Vol. 12/1, p. 43;Beilstein Vol. 6, p. 177).

[0110] The average q values can be determined by determining thecomposition of the phosphate mixture (molecular weight distribution) bymeans of a suitable method (gas chromatography (GC), high pressureliquid chromatography (HPLC), gel permeation chromatography (GPC)) andcalculating the average values of q therefrom.

[0111] Phosphonate amines are preferably compounds of formula (V)

A_(3-y)-NB¹ _(y)  (V)

[0112] in which

[0113] A represents a radical of formula (Va)

[0114] or (Vb)

[0115] R¹¹ and R¹² are each independently of the other unsubstituted orsubstituted C₁-C₁₀-alkyl or unsubstituted or substituted C₆-C₁₀-aryl,

[0116] R¹³ and R¹⁴ are each independently of the other unsubstituted orsubstituted C₁-C₁₀-alkyl or unsubstituted or substituted C₆-C₁₀-aryl, or

[0117] R¹³ and R¹⁴ together represent unsubstituted or substitutedC₃-C₁₀-alkylene,

[0118] y represents the numerical values 0, 1 or 2, and

[0119] the substituents B¹ are each independently hydrogen, optionallyhalogenated C₂-C₈-alkyl, unsubstituted or substituted C₆-C₁₀-aryl.

[0120] The substituents B¹ are preferably each independently hydrogen,ethyl, n- or isopropyl, which may be substituted by halogen;C₆-C₁₀-aryl, especially phenyl or naphthyl, which is unsubstituted orsubstituted by C₁-C₄-alkyl and/or by halogen.

[0121] Alkyl in R¹¹, R¹², R¹³ and R¹⁴, each independently of the others,is preferably methyl, ethyl, n-propyl, isopropyl, n-, iso-, sec.- ortert.-butyl, pentyl or hexyl.

[0122] Substituted alkyl in R¹¹, R¹², R¹³ and R¹⁴, each independently ofthe others, is preferably C₁-C₁₀-alkyl substituted by halogen,especially mono- or di-substituted methyl, ethyl, n-propyl, isopropyl,n-, iso-, sec.- or tert.-butyl, pentyl or hexyl.

[0123] C₆-C₁₀-Aryl in R¹¹, R¹², R¹³ and R¹⁴, each independently of theothers, is preferably phenyl, naphthyl or binaphthyl, especiallyo-phenyl, o-naphthyl, o-binaphthyl, which may be substituted (generallymono-, di- or tri-substituted) by halogen.

[0124] R¹³ and R¹⁴ may form a ring structure together with the oxygenatoms to which they are directly bonded and the phosphorus atom.

[0125] The following are mentioned by way of preferred examples:5,5,5′,5′,5″,5″-hexamethyltris(1,3,2-dioxaphosphorinane-methane)amino-2,2′,2″-trioxideof formula (Va-1)

[0126] (test product XPM 1000, Solutia Inc., St. Louis, USA)

[0127] 1,3,2-dioxaphosphorinane-2-methaneamine,N-butyl-N[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)methyl]-5,5-dimethyl-,P,2-dioxides; 1,3,2-dioxaphosphorinane-2-methaneamine,N-[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)methyl]-5,5-dimethyl-N-phenyl-,P,2-dioxide; 1,3,2-dioxaphosphorinane-2-methaneamine, N,N-dibutyl-5,5-dimethyl-, 2-oxide, 1,3,2-dioxaphosphorinane-2-methaneimine,N-[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)methyl]-N-ethyl-5,5-dimethyl-,P,2-dioxide, 1,3,2-dioxaphosphorinane-2-methaneamine,N-butyl-N-[(5,5-dichloromethyl-1,3,2-dioxaphosphorinan-2-yl)-methyl]-5,5-di-chloromethyl-,P,2-dioxide, 1,3,2-dioxaphosphorinane -2-methaneamine,N-[(5,5-di-chloromethyl-1,3,2-dioxaphosphorinan-2-yl)methyl]-5,5-dichloromethyl-N-phenyl-, P,2-dioxide;1,3,2-dioxaphosphorinane -2-methaneamine,N,N-di-(4-chlorobutyl)-5,5-dimethyl-2-oxides; 1,3,2-dioxaphosphorinane-2-methaneimine,N-[(5,5-dimethyl-1,3,2-dioxaphosphorinan-2-yl)-methane]-N-(2-chloroethyl)-5,5-di(chloromethyl)-,P,2-dioxide.

[0128] Also preferred are:

[0129] compounds of formula (Va-2) or (Va-3)

[0130] wherein

[0131] R¹¹, R¹², R¹³ and R¹⁴ are as defined above.

[0132] Compounds of formulae (Va-2) and (Va-1) are particularlypreferred.

[0133] The preparation of the phosphonate amines is described, forexample, in U.S. Pat. No. 5,844,028.

[0134] Phosphazenes are compounds of formulae (VIa) and (VIb)

[0135] wherein

[0136] the radicals R are each identical or different and representamino, C₁-C₈-alkyl or C₁-C₈-alkoxy each optionally halogenated,preferably halogenated by fluorine, C₅- to C₆-cycloalkyl, C₆- toC₂₀-aryl, preferably phenyl or naphthyl, C₆- to C₂₀-aryloxy, preferablyphenoxy, naphthyloxy, or C₇- to C₁₂-aralkyl, preferablyphenyl-C₁-C₄-alkyl, each optionally substituted by alkyl, preferablyC₁-C₄-alkyl, and/or by halogen, preferably chlorine and/or bromine,

[0137] k represents 0 or a number from 1 to 15, preferably a number from1 to 10.

[0138] The following may be mentioned by way of examples:

[0139] propoxyphosphazene, phenoxyphosphazene, methylphenoxyphosphazene,aminophosphazene and fluoroalkylphosphazenes.

[0140] Phenoxyphosphazene is preferred.

[0141] The phosphazenes may be used alone or in the form of a mixturewith other phosphorus-containing flameproofing agents. The radical R mayalways be identical, or two or more radicals in formulae (VIa) and (VIb)may be different.

[0142] Phosphazenes and their preparation are described, for example, inEP-A 728 811, DE-A 1 961 668 and WO 97/40092.

[0143] The flameproofing agents may be used alone or in any desiredmixture with one another or in admixture with other flameproofingagents.

[0144] Component D

[0145] Talc is understood as being a naturally occurring or asynthetically prepared talc.

[0146] Pure talc has the chemical composition 3 MgO.4SiO₂.H₂O andaccordingly has an MgO content of 31.9 wt. %, an SiO₂ content of 63.4wt. % and a content of chemically bonded water of 4.8 wt. %. It is asilicate having a layered structure.

[0147] Naturally occurring talc materials generally do not have theideal composition mentioned above, since they are rendered impure by thepartial replacement of the magnesium by other elements, by the partialreplacement of silicon by, for example, aluminium, and/or byintergrowths with other minerals such as, for example, dolomite,magnesite and chlorite.

[0148] The particular types of talc within the scope of the inventionare distinguished by an especially high purity, characterised by an MgOcontent of from 28 to 35 wt. %, preferably from 30 to 33 wt. %,particularly preferably from 30.5 to 32 wt. %, and an SiO₂ content offrom 55 to 65 wt. %, preferably from 58 to 64 wt. %, particularlypreferably from 60 to 62.5 wt. %. Preferred types of talc are furtherdistinguished by an Al₂O₃ content of less than 5 wt. %, particularlypreferably less than 1 wt. %, especially less than 0.7 wt. %.

[0149] Commercially available types of talc which correspond to thatdefinition are, for example, Naintsch A3, A7, A10, A30 and NaintschPrever M30 from Naintsch Mineralwerke GmbH (Graz, Austria), and thetypes Finntalc MO5SL, MO3 and M20SL which are marketed by Omya GmbH(Cologne).

[0150] Types of talc which are not within the scope of the inventionare, for example, Naintsch SE-Standard, Naintsch SE-Super, NaintschSE-Micro and Naintsch ST 10, 15, 20, 30 and 60, all of which aremarketed by Naintsch Mineralwerke GmbH.

[0151] The use of the talc according to the invention in the form offinely ground types having a mean largest particle size d₅₀ of <20 μm,preferably <10 μm, particularly preferably <5 μm, very particularlypreferably <2.5 μm, is especially advantageous. By using such fine typesof talc, an improved (notched bar) impact strength in particular isachieved, without the remaining properties (flame resistance, rigidity,flow properties, resistance to stress cracking, etc.) being impairedthereby.

[0152] The talc can be surface-treated, for example silanised, in orderto ensure better compatibility with the polymer. With regard to theprocessing and preparation of the moulding compositions, the use ofcompacted talc is also advantageous.

[0153] Further Additives E

[0154] The compositions according to the invention may contain asanti-dripping agents preferably fluorinated polyolefins E.1 in an amountof up to 3 parts by weight, preferably from 0.01 to 1 part by weight,based on the total composition.

[0155] Fluorinated polyolefins are generally known (see, for example,EP-A 640 655). A commercially available product is, for example, Teflon®30 N from DuPont.

[0156] The fluorinated polyolefins may also be used in the form of acoagulated mixture of emulsions of the fluorinated polyolefins withemulsions of the graft polymers B) or with an emulsion of a copolymerpreferably based on styrene/acrylonitrile, the fluorinated polyolefin inthe form of an emulsion being mixed with an emulsion of the graftpolymer or copolymer and subsequently coagulated.

[0157] The fluorinated polyolefins may also be used in the form of apre-compound with the graft polymer B or with a copolymer preferablybased on styrene/acrylonitrile. The fluorinated polyolefins are mixed inthe form of a powder with a powder or granulate of the graft polymer orcopolymer and are compounded in the melt generally at temperatures offrom 208 to 330° C. in conventional apparatuses such as internalkneaders, extruders or double-shaft screws.

[0158] The fluorinated polyolefins may also be used in the form of amasterbatch, which is prepared by emulsion polymerisation of at leastone monoethylenically unsaturated monomer in the presence of an aqueousdispersion of the fluorinated polyolefin. Preferred monomer componentsare styrene, acrylonitrile and mixtures thereof. The polymer is used inthe form of a pourable powder after acid precipitation and subsequentdrying.

[0159] The coagulates, pre-compounds and masterbatches usually havesolids contents of fluorinated polyolefin of from 5 to 95 wt. %,preferably from 7 to 60 wt. %.

[0160] The compositions according to the invention may also containfurther polymers.

[0161] There are suitable preferably vinyl (co)polymers (E.2) of atleast one monomer from the group of the vinyl aromatic compounds, vinylcyanides (unsaturated nitrites), (meth)acrylic acid (C₁-C₈)-alkylesters, unsaturated carboxylic acids and derivatives (such as anhydridesand imides) of unsaturated carboxylic acids. There are suitableespecially (co)polymers of

[0162] E.2.1 from 50 to 99 parts by weight, preferably from 60 to 90parts by weight, of vinyl aromatic compounds and/or vinyl aromaticcompounds substituted at the nucleus, such as, for example, styrene,α-methylstyrene, p-methylstyrene, p-chlorostyrene, and/or methacrylicacid (C₁-C₈)-alkyl esters, such as, for example, methyl methacrylate,ethyl methacrylate, and

[0163] E.2.2 from 1 to 50 parts by weight, preferably from 10 to 40parts by weight, of vinyl cyanides (unsaturated nitriles), such asacrylonitrile and methacrylonitrile, and/or (meth)acrylic acid(C₁-C₈)-alkyl esters (such as, for example, methyl methacrylate, n-butylacrylate, tert.-butyl acrylate) and/or unsaturated carboxylic acids(such as maleic acid) and/or derivatives (such as anhydrides and imides)of unsaturated carboxylic acids (for example maleic anhydride andN-phenyl-maleimide).

[0164] The (co)polymers E.2 are resin-like, thermoplastic andrubber-free.

[0165] Particular preference is given to the copolymer of E.2.1 styreneand E.2.2 acrylonitrile.

[0166] The (co)polymers according to E.2 are known and can be preparedby free-radical polymerisation, especially by emulsion, suspension,solution or mass polymerisation. The (co)polymers according to componentE.2 preferably have molecular weights M_(w) (weight average, determinedby light scattering or sedimentation) of from 15,000 to 200,000.

[0167] Also suitable are polyalkylene terephthalates (E.3) such as aredescribed in EP-A-841 187.

[0168] Preference is given to polyalkylene terephthalates which havebeen prepared from terephthalic acid and/or reactive derivatives thereof(e.g. dialkyl esters thereof) and ethylene glycol and/or 1,4-butanediol,and mixtures of those polyalkylene terephthalates.

[0169] The compositions according to the invention preferably containvinyl (co)polymers, polyalkylene terephthalates or mixtures thereof upto an amount of 30 wt. %, preferably up to 15 wt. %, based on the totalcomposition.

[0170] The moulding compositions according to the invention may containat least one other of the conventional additives, such as, for example,anti-dripping agents, lubricants and mould-release agents, nucleatingagents, antistatics, stabilisers, colourings and pigments, as well asfillers and reinforcing agents other than talc.

[0171] The moulding compositions according to the invention containingthe above-mentioned components and, optionally, additives are preparedby mixing the respective constituents in a known manner andmelt-compounding or melt-extruding them at temperatures of from 200° C.to 300° C. in conventional apparatuses such as internal kneaders,extruders and double-shaft screws.

[0172] The individual constituents may be mixed in a known manner eitherin succession or simultaneously, either at approximately 20° C. (roomtemperature) or at a higher temperature.

[0173] Owing to their excellent flame resistance and their good otherproperties, such as, for example, ESC behaviour (resistance to stresscracking), rigidity, dimensional stability under heat, flowability andlack of warping, the thermoplastic moulding compositions according tothe invention are suitable for the production of moulded bodies of anykind, especially of thin-walled parts having increased requirements asregards flame resistance.

[0174] The moulded bodies can be produced, for example, by injectionmoulding or extrusion. Examples of moulded bodies which can be producedare: casing parts of any kind, for example for domestic appliances, suchas juice extractors, coffee machines, mixers; for office equipment, suchas monitors, (portable) computers, printers and copiers. Other possiblefields of application are covering plates and electrical installationchannels for the construction sector as well as parts for the motorvehicle sector. The moulding compositions can also be used in the fieldof electrical engineering, for example for switches, sockets and circuitboards.

[0175] The invention relates also to a process for the preparation ofthe composition, to the use of the composition in the production ofmoulded bodies, and to the moulded bodies themselves.

EXAMPLES

[0176] Component A-1

[0177] Polycarbonate based on bisphenol A having a relative solutionviscosity of 1.28, measured in methylene chloride at 25° C. and in aconcentration of 0.5 g/100 ml.

[0178] Component A-2

[0179] As component A-1, but having a relative solution viscosity of1.20.

[0180] Component A-3

[0181] As component A-1, but having a relative solution viscosity of1.25.

[0182] Component B-1

[0183] Graft polymer, prepared by emulsion polymerisation, of 45 partsby weight of styrene and acrylonitrile in a ratio of 72:28 with 55 partsby weight of a particulate crosslinked polybutadiene rubber (meanparticle diameter d₅₀=from 0.3 to 0.4 μm).

[0184] Component B-2

[0185] Graft polymer of 83 parts by weight of a copolymer of styrene andacrylonitrile in a ratio of 75.5 with 24.5 parts by weight ofcrosslinked polybutadiene-styrene rubber having a styrene content of10%, prepared by mass polymerisation (mean particle diameter d₅₀=0.5μm).

[0186] Component C

[0187] C.1 Bisphenol-A-based phosphate

[0188] C.2 Resorcinol-based phosphate

[0189] In order to determine the average q value, the proportions of theoligomeric phosphates were first determined by HPLC measurements: columntype: LiChrosorp RP-8 eluant in the gradient: acetonitrile/water 50:50to 100:0 concentration: 5 mg/ml

[0190] The number-weighted average values were then determined from theproportions of the individual components (mono- and oligo-phosphates) byknown processes.

[0191] Component D

[0192] D1: Naintsch Prever M30, talc from Naintsch Mineralwerke GmbH(Graz, Austria) having an MgO content of 31.2 wt. %, an SiO₂ content of62.5 wt. % and an Al₂O₃ content of 0.7 wt. %.

[0193] D2: Finntalc M05SL, talc from Mondo Minerals Oy (Helsinki,Finland), marketed by Omya GmbH (Cologne), having an MgO content of 31wt. %, an SiO₂ content of 61 wt. % and an Al₂O₃ content of 0.3 wt. %.

[0194] D3: Finntalc M20SL, talc from Mondo Minerals Oy having an MgOcontent of 31 wt. %, an SiO₂ content of 61 wt. % and an Al₂O₃ content of0.3 wt. %.

[0195] D4: Naintsch A3, talc from Naintsch Mineralwerke GmbH having anMgO content of 31.5 wt. %, an SiO₂ content of 62.0 wt. % and an Al₂O₃content of 0.4 wt. %.

[0196] D5: Naintsch SE-Super, talc from Naintsch Mineralwerke GmbHhaving an MgO content of 22 wt. % and an SiO₂ content of 17 wt. %. Al₂O₃was not detected.

[0197] D6: Naintsch ST10, talc from Naintsch Mineralwerke GmbH having anMgO content of 30 wt. %, an SiO₂ content of 48 wt. % and an Al₂O₃content of 10.5 wt. %.

[0198] The data given with regard to the indicated chemical compositionsare manufacturers' data. Analysis is carried out by methods known in theliterature (for example by X-ray fluorescence spectroscopy or atomadsorption spectroscopy or calorimetry).

[0199] Component E-1

[0200] The polytetrafluoroethylene emulsion is prepared byco-precipitation of a mixture of aqueous emulsions of the graft polymer(component B) and of a tetrafluoroethylene polymer. The ratio by weightof graft polymer B to the tetrafluoroethylene polymer E in the coagulateis 90 wt. % to 10 wt. %. The tetrafluoroethylene polymer emulsion has asolids content of 60 wt. %, the mean PTFE particle diameter is from 0.05to 0.5 μm. The graft polymer emulsion has a solids content of 34 wt. %and a mean latex particle diameter of from 0.3 to 0.4 μm.

[0201] Preparation of E-1

[0202] The emulsion of the tetrafluoroethylene polymer (Teflon 30 N fromDuPont) is mixed with the emulsion of the graft polymer B and stabilisedwith 1.8 wt. %, based on polymer solid, of phenolic antioxidants. Atfrom 85 to 95° C., the mixture is coagulated with an aqueous solution ofMgSO₄ (Epsom salts) and acetic acid at pH from 4 to 5, filtered andwashed until virtually free of electrolyte, and is subsequently freed ofthe majority of the water by centrifugation and then dried to a powderat 100° C. The powder can then be compounded with the other componentsin the described apparatuses.

[0203] Component E-2

[0204] Blendex 449: PTFE preparation from General Electric Plastics,consisting of 50 wt. % PTFE and 50 wt. % SAN copolymer.

[0205] Component E-3

[0206] Styrene/acrylonitrile copolymer having a styrene/acrylonitrileratio of 72:28 and an intrinsic viscosity of 0.55 dl/g (measured indimethylformamide at 20° C.).

[0207] Component E-4

[0208] Phosphite stabiliser

[0209] Component E-5

[0210] Pentaerythritol tetrastearate as mould-release agent.

[0211] Preparation and Testing of the Moulding Compositions According tothe Invention

[0212] Components A to E are mixed in a 3 liter kneader. The mouldedbodies are produced on an Arburg 270E injection-moulding machine at 240°C.

[0213] The stress cracking behaviour is tested on rods measuring 80×10×4mm. The test medium used is a mixture of 60 vol. % toluene and 40 vol. %isopropanol. The test specimens are pre-expanded by means of a circulararc template (pre-extension from 1.2 to 2.4%) and stored in the testmedium at room temperature for 5 minutes.

[0214] The stress cracking behaviour is assessed by means of theflexural elongation which at least is necessary for the rod to breakwithin the 5-minute exposure time in the test medium.

[0215] The flame resistance is determined according to UL94V on rodshaving a thickness of 1.2 mm.

[0216] The tensile modulus is measured according to ISO 527/DIN 53 457.TABLE 1 Composition and properties Example/ Components 1 2 3 4 5 C1* C2*A1 32.3 32.3 32.3 32.3 32.3 32.3 32.3 A2 32.3 32.3 32.3 32.3 32.3 32.332.3 A3 B1 8.6 8.6 5.0 5.0 5.0 5.0 5.0 C1 C2 10.9 10.9 10.9 10.9 10.910.9 10.9 D1 10.0 D2 10.0 10.0 D3 10.0 D4 10.0 D5 10.0 D6 10.0 E1 4.04.0 4.0 4.0 4.0 E2 0.8 0.8 E3 4.6 4.6 5.0 5.0 5.0 5.0 5.0 E4 0.1 0.1 0.10.1 0.1 0.1 0.1 E5 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Properties: Modulus ofelasticity [GPa] 4.0 4.0 4.0 3.9 4.0 3.1 3.5 ESC Flexural elongation at2.4 2.2 2.2 >2.4 2.0 2.0 2.4 break [%] UL94V at Rating V0 V0 V0 V0 V0 V2V1 1.2 mm (Total after-burning time) (19 s) (11 s) (35 s) (8 s) (13 s)(81 s) (61 s) Example/ Components 6 7 8 9 10 11 12 C3* 13 C4* 14 15 A134.8 35.8 36.8 27.3 31.6 26.7 32.8 33.1 31.3 30.3 A2 34.8 35.8 36.8 27.331.6 26.7 32.8 33.1 31.3 30.3 A3 64.9 67.0 B1 5.0 5.0 5.0 8.6 4.9 4.96.5 6.7 7.1 7.2 2.0 B2 19.9 19.9 C1 12.8 12.8 14.0 14.4 15.1 15.3 14.014.0 C2 10.9 10.9 10.9 10.9 D1 D2 5.0 3.0 1.0 20.0 9.8 19.6 3.0 1.0 D3D4 2.0 2.0 D5 D6 E1 4.0 4.0 4.0 3.9 3.9 4.6 4.7 4.6 4.7 E2 0.8 1.0 1.0E3 5.0 5.0 5.0 4.6 4.9 4.9 6.5 6.7 6.1 6.1 E4 0.1 0.1 0.1 0.1 0.1 0.10.1 0.1 0.1 0.1 0.1 0.1 E5 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.40.4 Properties: Modulus of [GPa] 3.4 3.1 2.8 5.5 3.9 5.4 2.9 2.6 2.8 2.5n.b. n.b. elasticity Flexural elonga- 2.2 2.2 1.8 2.4 2.4 1.8 >2.4 2.22.4 2.0 2.2 2.2 ESC tion at break [%] UL94V at Rating V0 V0 V0 V0 V0 V0V0 V2 V0 V2 V0 V0 1.2 mm (Total after- (19 s) (27 s) (43 s) (36 s) (27s) (30 s) (23 s) (56 s) (42 s) (68 s) (17 s) (44 s) burning time)

[0217] It will be seen from Table 1 that by using highly pure types oftalc (Examples 1 to 5), improved flame resistance at a wall thickness of1.2 mm (reduced after-burning times as well as a reduced drippingtendency) and a higher modulus of elasticity are achieved than whenother types of talc are used in the same concentration (Comparisons 1and 2). Only with highly pure talc is a V-0 rating achieved in the UL94Vtest at a wall thickness of 1.2 mm. The moulding compositions arefurther distinguished by an unusually good resistance to stresscracking. The nature of the PTFE preparation used has only a negligibleeffect on those properties (Examples 2 and 3). The effect is found withvarious phosphorus-containing flameproofing agents.

[0218] As the concentration of talc increases, the after-burning timesare initially increasingly reduced within certain limits, which dependon the composition in question and on the nature of the flameproofingagent (Examples 3 and 6 to 8). The modulus of elasticity rises linearlywith the talc content, an increase in the modulus of elasticity of up to0.15 GPa per 1 wt. % of added talc being achieved in the case of highlypure types of talc, whereas markedly smaller increases in the modulus ofelasticity are observed when other types of talc are used (Comparisons 1and 2).

[0219] Even with very low talc contents of, for example, 1 wt. % it ispossible, in combination with different phosphorus-containingflameproofing agents, to achieve a V-0 rating in the UL94V test at awall thickness of 1.2 mm, and a marked improvement in the ESC behaviour(Examples 7, 8, 12 and 13). Comparison of Example 12 with Comparison 3or Example 13 with Comparison 4 shows the positive effect of the talc onthe flame resistance (after-burning time and dripping tendency) and onthe resistance to stress cracking and the rigidity of the mouldingcomposition. By using low concentrations of talc, for example from 1 to5 wt. %, it is possible to prepare moulding compositions which haveexcellent flame resistance and a balance between increased rigidity andhigh strength, as well as very good ESC behaviour.

[0220] A V-0 rating in the UL94V test at a wall thickness of 1.2 mm isobtained, in combination with various phosphorus-containingflameproofing agents, also in the case of high talc contents of, forexample, from 10 to 20 wt. % (for example, Examples 9 and 11). Thosemoulding compositions having a high talc content are distinguished bytheir excellent flame resistance and especially high rigidity, while atthe same time being surprisingly high in strength.

[0221] If C.1 (bisphenol-A-based phosphate) is used as thephosphorus-containing flameproofing agent, an especially good ESCbehaviour is obtained as compared with the resorcinol-based phosphate(C.2) especially in the case of low talc contents of, for example, lessthan or equal to 3 wt. % (Examples 7 and 8 and 12 and 13). However, evenin the case of the resorcinol-based phosphate (C.2), an improvement inthe ESC behaviour is achieved by the addition of talc (Examples 7 and8).

[0222] The described positive effect of the particular talc on the flameresistance is observed both when only one polycarbonate is used and whena mixture of several polycarbonates of different solution viscosities isused (Examples 7, 8, 12 and 13).

[0223] The effect is observed also when mass ABS (Example 14) ormixtures of mass and emulsion ABS (Example 15) are used as impactmodifier.

1. Compositions containing polycarbonate, at least one impact modifier,at least one phosphorus-containing flameproofing agent, and a talc ofhigh purity, characterised by an MgO content of from 28 to 35 wt. %, anSiO₂ content of from 55 to 65 wt. % and an Al₂O₃ content of <5 wt. %, ineach case based on the talc.
 2. Compositions according to claim 1containing from 40 to 98 wt. % of at least one aromatic polycarbonate,from 0.5 to 50 wt. % of at least one graft polymer, from 0.5 to 40 wt. %of at least one phosphorus-containing flameproofing agent, and from 0.05to 40 wt. % of talc.
 3. Compositions according to claim 1 containingfrom 45 to 95 wt. % of at least one aromatic polycarbonate, from 1 to 35wt. % of at least one graft polymer, from 2 to 20 wt. % of at least onephosphorus-containing flameproofing agent, and from 0.5 to 30 wt. % oftalc.
 4. Compositions according to claim 1 to 3 containing a talc,characterised by an MgO content of from 30 to 33 wt. %, an SiO₂ contentof from 58 to 64 wt. % and an Al₂O₃ content of <1.0 wt. %, in each casebased on the talc.
 5. Compositions according to claim 1 to 3 containinga talc, characterised by an MgO content of from 30.5 to 32 wt. %, anSiO₂ content of from 60 to 62.5 wt. % and an Al₂O₃ content of <0.7 wt.%, in each case based on the talc.
 6. Compositions according to claim 1to 5, wherein the talc is additionally characterised in that the talcparticles having a largest diameter of 2.5 μm or less make up an amountby weight of at least 50% of the talc (d₅₀ less than or equal to 2.5μm).
 7. Compositions according to claim 1 to 6 containing as impactmodifier one or more graft polymers of from 5 to 95 wt. % of at leastone vinyl monomer with from 95 to 5 wt. % of at least one graft basehaving a glass transition temperature <10° C.
 8. Compositions accordingto claim 7 containing graft polymers based on diene, EP(D)M, acrylate orsilicone rubbers.
 9. Compositions according to claim 7 containing anemulsion or mass ABS or mixtures thereof as impact modifier. 10.Compositions according to claim 1 to 9 containing at least onephosphorus-containing flameproofing agent selected from the groups ofthe mono- and oligo-phosphoric acid or phosphonic acid esters,phosphonate amines and phosphazenes.
 11. Compositions according to claim1 to 10 containing as flameproofing agent at least one phosphoruscompound of the general formula (IV)

wherein R¹, R², R³ and R⁴ are each independently of the othersoptionally halogenated C₁- to C₈-alkyl, or C₅- to C₆-cycloalkyl, C₆- toC₂₀-aryl or C₇- to C₁₂-aralkyl each optionally substituted by alkyland/or by halogen, the substituents n are each independently of theothers 0 or 1, q represents from 0 to 30, and X represents a mono- orpoly-nuclear aromatic radical having from 6 to 30 carbon atoms, or alinear or branched aliphatic radical having from 2 to 30 carbon atomswhich may be OH-substituted and contain up to 8 ether bonds. 12.Compositions according to claim 1 to 11 containing as flameproofingagent at least one compound of formula

wherein R¹, R², R³ and R⁴ are each independently of the otherC₁-C₈-alkyl and/or optionally alkyl-substituted C₅-C₆-cycloalkyl,C₆-C₁₀-aryl or C₇-C₁₂-aralkyl, the substituents n are each independentlyof the others 0 or 1, the substituents 1 are each independently of theother 0, 1, 2, 3 or 4, q is from 0.3 to 20, R⁵ and R⁶ are eachindependently of the other C₁-C₄-alkyl, and Y representsC₁-C₇-alkylidene, C₁-C₇-alkylene, C₅-C₁₂-cycloalkylene,C₅-C₁₂-cycloalkylidene, —O—, —S—, —SO—, SO₂ or —CO—.
 13. Compositionsaccording to claim 1 to 12 containing as flameproofing agent a compoundof the formula

wherein q is from 0.3 to
 10. 14. Compositions according to claim 1 to 13containing vinyl (co)polymers, polyalkylene terephthalates or mixturesthereof.
 15. Compositions according to claim 14 containing up to 30 wt.%, based on the total composition, of a vinyl copolymer. 16.Compositions according to claim 1 to 15 containing further commerciallyavailable additives, such as, for example, anti-dripping agents,lubricants and mould-release agents, nucleating agents, antistatics,stabilisers, colourings and pigments, as well as fillers and reinforcingagents other than talc.
 17. Compositions according to claim 1 to 16containing as anti-dripping agent a fluorinated polyolefin, optionallyused in the form of a coagulate, pre-compound or masterbatch with agraft polymer according to claim 7 or with a vinyl (co)polymer. 18.Polycarbonate compositions containing from 50 to 90 wt. % of at leastone aromatic polycarbonate, from 1.5 to 25 wt. % of at least one graftpolymer according to claim 9, from 2 to 20 wt. % of at least oneflameproofing agent according to claim 11, from 0 to 20 wt. % of a vinyl(co)polymer, and from 1 to 20 wt. % of a talc according to thedefinition in claim 4, the sum of the components being
 100. 19.Polycarbonate compositions containing from 50 to 90 wt. % of at leastone aromatic polycarbonate, from 1.5 to 25 wt. % of at least one graftpolymer according to claim 9, from 2 to 20 wt. % of at least oneflameproofing agent according to claim 12, from 0 to 20 wt. % of a vinyl(co)polymer, and from 1 to 20 wt. % of a talc according to thedefinition in claim 5, the sum of the components being
 100. 20.Polycarbonate compositions according to one or more of the precedingclaims, characterised in that they pass the UL94V test with V-0 at awall thickness less than or equal to 1.5 mm.
 21. Process for thepreparation of the polycarbonate compositions according to claim 1,wherein the individual components are mixed and compounded at elevatedtemperature.
 22. Use of the polycarbonate compositions according to oneor more of the preceding claims in the production of moulded bodies andmouldings of any kind.
 23. Moulded bodies and mouldings obtainable fromthe polycarbonate compositions according to one or more of the precedingclaims.